Clamps are often used in the woodworking field to join and hold components together while adhesives and/or fasteners are used to maintain the components together. One particular group of clamps that are often used includes the arm, body or bar clamp or other similar type clamp, hereinafter referred to as bar clamps. The bar clamp includes a moveable member, such as a slide jaw, configured to move along a length of the bar clamp, such as along a guide rail, to cause compression or squeezing of components of a workpiece. This compressive force is the result of the moveable member compressing the components against an opposing member, such as a fixed jaw, of the bar clamp. The opposing member is suitable in strength to allow a substantial amount of compressive force to be applied to the components of the workpiece. Such compressive force is desired, and often needed, to ensure that the components are properly joined and aligned during fastening of the same.
In certain applications it has become advantageous to generate compressive forces in multiple directions with respect to components of a workpiece. For example, with continued reference to the bar clamp, at times it is advantageous to generate forces both longitudinally along the length of the bar clamp as well as laterally, i.e. generally perpendicular to the longitudinal force, to ensure that the components maintain position with respect to one another during attachment. In this regard, few manufactures have developed products capable of generating multiple forces onto a workpiece, particularly with respect to bar clamps. In the only known instance, an edge clamp, that is attachable to the bar clamp and able to generate a force generally perpendicular with respect to the compressive forces generated along a length of the bar clamp, is available for purchase, separate from the bar clamp. However, these edge clamps provide little more function than a positioning means for a workpiece as the clamps are incapable of substantial compressive force, as compared to the compressive force generated along the length of the bar clamp. This is due to the lack of support or counterforce acting upon the workpiece as the edge clamp applies the lateral compressive force to the workpiece. At best, the only resistance to the edge clamp is the friction force generated between the components of the workpiece and the bar clamp. Accordingly, as soon as the compressive force of the edge clamp overcomes the friction force, the components of the workpiece moves away from the bar clamp thereby rendering the edge clamp ineffective for applying meaningful compressive force.
In one particular application, it has been discovered that existing bar clamps, along with edge clamps, are ineffective for joining longer and wider workpiece components together, such as boards, panels or otherwise. This is due to the inability of the bar clamp to generate suitable lateral compressive force, as described above. Accordingly, should one desire to form a multi-layered panel, such as a plywood board or the like, they are required to purchase specialized clamps, which incurs cost for the additional tool and added steps to the overall production of a final workpiece. This is particularly problematic when attaching veneer to a base board, wherein a particular wood finish is desired.
In another aspect, with the exception of the use of a side clamp, prior bar clamps have been one dimensional with respect to clamping forces. This is because the only clamping force provided is between a slide jaw and fixed jaw of the bar clamp. If additional clamping forces are desired, whether on the same workpiece or a different workpiece, additional clamps must be used, which can be costly and cumbersome in use.
In view of the foregoing, there is a need for methods and devices for improving available clamping forces onto a workpiece. More so, there is a need for an improved bar clamp assembly capable of providing improved multiple compressive forces to a workpiece, particularly at least one suitable force that is generally perpendicular to compressive force applied along a length of the bar clamp.